So what happens if a procedure doesn't contain the RET command?

One of the tips that J. Heumann mentioned in his article about writing use cases Download writing use caseswas “kick out the CRUD (create, read, update and delete)”. Why do you think we need to avoid CRUD in use cases?

Consider a view v whose definition solely refers to r. Does a user with update permission on v need to have update permission on r as well? So, why?

The Finance team wants to calculate a VAT (8%) on the amount of the stay reservations in the database. However, the team wants to calculate the VAT after the discounts are applied on the prices. In addition, it is important to remember if there is no discount/offers, then the value is NULL in the TRAVELS table. Create a procedure called VATCalculator to calculate the VAT amount and return with the corresponding travel ID. In addition, execute the procedure to account for NULL values and send the respective result to the team. The VAT value should be rounded to 2 decimals.